Electric conduit bushing



Jan. 27, 1931. w. H. VIBBER 1,790,254

ELECTRIC CONDUIT BUSHING Filed June 19, 1928 Patented Jan. 27, 1931 UNITED STATES WHEELER H. VIBBER, 01' NEW LONDON, CONNECTICUT ELECTRIC OONDUI'I BUSHING Application filed June 19,

This invention-relates to an improvement in so-called conduit-bushings or terminals which are adapted to be secured to the ends of electric conduits for the double purpose of providing a smooth non-abrading termmal through which the circuit-wires may pass and also providin means whereby the conduit may be electrically grounded.

I am aware that many fittings have been 1" devised for thepurpose above mentioned but they have all been more or less awkward to use," owing to the difficulty of attaching ring-portion adapted to be secured to the end 5 of an electric conduit and a lug upstanding from the outer face of the said ring-portion and provided with a screw-receiving bore having its axis disposed transverse to the axis of the said ring-portion.

In the accompanying drawings:

Fig. 1 is a view in front elevation of a junction-box having two, conduit-bushings constructed in accordance with my invention, installed therein;

Fig. 2 is an enlarged-scale top or plan view of my improved conduit-bushing;

Fig. 3 is a view thereof in elevation;

Fig. 4 is a similar view but viewing the bushing at a right angle from the position in 40 which it is shown in Fig. 3;

Fig. 5 is a transverse sectional View on the line 5-5 of Fig. 2; and r Fig. 6 is a view corresponding to Fig. 5 but showing a modified form of grounding-lug.

In carrying out my invention as herein 1928. Serial No. 288,505.

shown my improved conduit-bushing comprises a ring-portion 10 formed with an internally-threaded axial bore 11 for the reception of the threaded outer end 12 of an electric conduit 13, the extreme outer end of which latter is adapted to abut against the inner face 14 of an annular stop-flange 15 overhanging the threaded bore ll-aforesaid and having its outer portion rounded as at 16 to provide a non-abrading surface against which the circuit-wires may rest.

Upstanding from the outer face of the ringportion 10 of my improved bushing is a grounding-lug 17 having parallel faces 18 and 19 formed transversely with an internally-threaded screw-receiving bore 20 adapted to receive a binding-screw 21. The periphery of the ring-member 10 is provided as shown with a number of vertical ribs 22 by means of which the bushing may be turned home upon the conduit 13.

In Fig. 1 of the drawings I have shown a junction-box 23 through the opposite walls of which projecttwo conduits 13, the ends of both of which are provided with my improved conduit-bushings. As is the usual practice. each of the said conduits has threaded upon it a binding-nut 2-1 engaging the outer face of the junction-box so as to bind the bushings against the inner wall thereof.

By reference to Fig. 1 of the drawings, it will be seen that by providing the upstanding grounding-lugs 17 equipped with binding-screws extending transverse to the axis of the ring-portion of the respective bushing, the installation of a grounding-wire 25 extending between the respective conduitbushings in accordance with the requirements of numerous electrical codes, is greatly facilitated, since it is a relatively simple matter to reach in-laterally through the open face of the junction-box 23, with a screwdriver or other tool and firmly bind the screws 21 upon the grounding-wire.

Heretofore it has been the general practice to provide the ring-members with radially-extending grounding-lugs through which binding-screws extend in a direction parallel with the axis of the ring, so that not only is the diameter of the bushing increased but the binding-screwis located in a position which renders-it very inaccessible to a screwdriver or other tool, since the cramped quarters such for instance as the interior of the outlet-box 23 renders it impossible to employ a screw-driver in a vertical position as is required by the vertical position of the screw. Under such circumstances, therefore, it is necessary for the electrician virtually to worry home the binding-screw.

In Figs. 1 to 5 of the drawings I have shown the head of the binding-screw 21 overhanging the bore 11 in positionto clam the grounding-wire against the face 18 o the I 40 .4 outer end face of the said ring-portion in a lug 17. Under certain conditions it may be desirable to reverse the screw so that it will bind the grounding-wire against the oppoface 26 and provided with a threaded screwreceiving bore extending at a right angle to it and, therefore, at, a slight angle with reference to the plane of the ring. In this instance, however, like that shown in the preceding figures, the said bore, and the binding-screw which it receives, is disposed transverse to the axis of the bushing-struc-- ture and is, therefore, conveniently available for the application of agrounding wire.

I claim I p 1 1. A conduit-bushing comprising a ringportion adapted to be secured to the end of a conduit; and a lug upstanding from the plane substantially parallelfwith the axis -thereof and provided with a screw-receiving bore having its axis disposed transverse to the axis of the said ring-portion.

2. A conduit-bushing comprising a ringportion adapted to be secured to the end of a conduit; and, a lug upstanding from the outer end face of the said ring-portion in a plane substantially parallel with .the axis thereof and provided with an internallythreaded screw-receiving bore having its axis disposed transverse to the axis of the said ring-portion.

3. A conduit-bushing comprising a ringportion adapted to be secured to'the 'end of a conduit; and a grounding-lug. upstanding.

- from the outer end face of the said ring .por-

tion in a plane substantially parallelwith the axis thereof and having substantially parallel opposite faces and provided with a screw-receiving bore intersecting both of the said parallel faces and having its axis disposed transverse to the axis ofthe said ringportion.

In testimony whereof, I have signed this specification.

WHEELER VIBBER. 

